Sometimes people think it's OK. It really isn't. If they never have a full body pic that's always a massive red flag.
It's still a tremendous waste of time on someone who has been continually lying to you.
Consider the time it takes for most folks to actually get a date while online dating. To learn that someone was deceiving you the entire time is enough to irritate even the most collected person.
i'd like to be careful with the word "lying" and "deceiving". If you ask them "might i ask, would you describe yourself as a skinny / fit person?" and they tell you they are, then they're lying.
If you're assuming "unless they disclose that they are fat, you're free to assume they're skinny" i think the fault's on your side, really.
Considering lack of a full body shot a red flag is fair game.
Saying anyone who doesn't disclose their body proportions is being "wilfully deceptive" is simply a bit too much, imho.
also, how is it a waste of time, specifically?
* do you go 'exclusive' without having ever met, therefore not contacting other online-daters anymore?
* does having a conversation with a person (unbeknownst that they are overweight) seriously have no value to you? and does writing a few IMs here and there really take up so much of your precious time? Let's not get carried away here, really.
How much of your time is really wasted on a person you end up not feeling attracted to.